Having spent several years actually doing work for most of the breakdown providers, my advice is to avoid ALL of the cheap ones that you've never previously heard of. If you can't take that, then you must read the terms and conditions, as there will be a lot of things you think you've paid for but won't get. That's over and above the specialist equipment charges(like getting the car out of a multi-storey carpark, winching off walls, loading an automatic that's stuck in park, getting a locked car out of your garage etc etc) that none of them cover.
If you're expecting a man in a van to turn up and try and fix the car, your options are the AA and RAC. But even that's unlikely to happen if you break down after 10pm, and they're notorious for sitting on jobs for hours and then passing them off to contractors. Green Flag's service has got a lot worse since they went to a few 'super-contractors' rather than lots of small ones. If I were going to start from scratch, I would choose Britannia Rescue as they were always the most professional and rarely caused problems.